[LangRef] nnan and ninf produce poison.

Clarify that violating nnan and ninf can lead to undefined behavior.
This allows more aggressive optimizations based on those assumptions.

Differential Revision: https://reviews.llvm.org/D47963



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337323 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed